Measure contributor experience

[perdasilva]

Description

As someone who cares about this community, I would like to be able to understand and measure our contributor experience to understand where and when improvement investment should be made. I would like to be able to generate a report which collects historically aggregated KPI information for the last n periods of d duration in days/weeks/months. Each of these should be capped to some reasonable amount, e.g. n*d <= 6 months. Initially, the report could just be a table of kpis by period.

Acceptance Criteria

1. Initial contributor experience KPIs defined
2. GitHub queries for each KPI defined
3. Report can be generated given: GitHub token, number of periods, period duration

[fgiloux]

A few proposals for KPI:

• mean and 95 percentile duration for first response to an issue / PR
• mean and 95 percentile duration for PR from open to merge/close
• mean and 95 percentile number of rebases per PR